设计模式之工厂模式

简单工厂不符合开闭原则，所以这里不把创建每个对象放在一个工厂里，而是把创建工厂抽象出来，每次创建一个具体对象由每个对象工厂自己常见，符合开闭原则。

#include<iostream>
using namespace std;
#include<string>

//简单工厂不符合开闭原则，所以这里不把创建每个水果对象放在一个工厂里，而是把创建工厂抽象出来，每次创建一个具体水果由每个对象工厂自己常见，达到开闭原则。

//抽象水果
class abstractFruit{
public:
    virtual void showName()=0;
};
//苹果
class apple:public abstractFruit{
public:
    virtual void showName()
    {
        cout<<"apple"<<endl;
    }
};
//梨
class pear:public abstractFruit{
public:
    virtual void showName()
    {
        cout<<"pear"<<endl;
    }
};
//香蕉
class banana:public abstractFruit{
public:
    virtual void showName()
    {
        cout<<"banana"<<endl;
    }
};

//抽象水果工厂
class abstractFactory{
public:
    virtual abstractFruit* createFruit()=0;
};

//苹果工厂
class appleFactory:public abstractFactory{
public:
    virtual abstractFruit* createFruit(){
        return new apple;
    }
};

//梨工厂
class pearFactory:public abstractFactory{
public:
    virtual abstractFruit* createFruit(){
        return new pear;
    }
};

//香蕉工厂
class bananaFactory:public abstractFactory{
public:
    virtual abstractFruit* createFruit(){
        return new banana;
    }
};


int main()
{
    //创建一个抽象工厂
    abstractFactory *factory=NULL;
    //创建一个抽象水果
    abstractFruit* fruit=NULL;
    
    
    //创建一个苹果
    factory=new appleFactory;
    fruit=factory->createFruit();
    fruit->showName();
    delete factory;
    delete fruit;
    
    //创建一个香蕉
    factory=new bananaFactory;
    fruit=factory->createFruit();
    fruit->showName();
    delete factory;
    delete fruit;
    
    //创建一个梨
    factory=new pearFactory;
    fruit=factory->createFruit();
    fruit->showName();
    delete factory;
    delete fruit;
    
    return 0;
}